Children are seemingly ever present in the world of Tomas Alfredson’s Tinker Tailor Soldier Spy, filling classrooms, occupying stairwells, observing with constant curiosity. The adults aren’t so different, except that while the kids fight and love and play in plain sight, the games that grown-ups play are far more insidious affairs.

The film’s first line is fitting: a question asked of late-night visitor Jim Prideaux (Mark Strong) by the weary, wary Control (John Hurt): “You weren’t followed?” Suspicion runs rampant between his underlings at “the Circus,” the code name for Britain’s Secret Intelligence Service, and in the heat of the Cold War, who can blame them? Once Prideaux’s mission in Budapest goes awry, Control is consequently ousted, and he takes right-hand man George Smiley (Gary Oldman) into forced retirement with him.

After Control’s passing, though, Smiley is brought back into the fold as part of a covert effort to uncover a Soviet turncoat. With the help of trustworthy protégé Peter Guillam (Benedict Cumberbatch) and alienated operative Ricki Tarr (Tom Hardy), Smiley has to determine which of his former colleagues it might be: the ambitious Percy Alleline (Toby Jones), the suave Bill Haydon (Colin Firth), the steadfast Roy Bland (Ciaran Hinds), or the submissive Toby Esterhase (David Dencik).

A condensed and unfailingly dense adaptation of John le Carré’s acclaimed espionage novel, the screenplay by Peter Straughan (The Debt) and the late Bridget O'Connor drops the audience right into the thick of things and trusts that we’ll be able to keep up with the numerous flashbacks and tricky jargon. (This writer found the film to be intimidating on first viewing, and illuminating on a second.) Director Tomas Alfredson maintains the chilly tone that defined his teen vampire breakout, Let the Right One In, training his camera on an entirely different group of bloodsuckers and casting equal doubt on the motives of every last one.

What follows is ultimately more of an effective character study than a riveting spy thriller, an emotional puzzle as much as a logical one, with Smiley serving as detective-cum-therapist to his friends and foes. “It was a good time back then,” laments Connie (Kathy Burke), a colleague similarly shoved out of the Circus. “It was a war, Connie,” George replies. “A war we could be proud of,” she insists. The central mystery of the mole’s identity is a gateway to issues like what people owe one another in addition to what they owe their country. It’s this sense of melancholy that comes with keeping the world safer than it knows at the cost of interpersonal trust, a sense of stakes more personal than political that keeps Alfredson’s chilly approach from leaving viewers out in the cold entirely.

That isn’t to say that this incarnation of Tinker Tailor skimps on the paranoia, with characters being framed within the confines of windows, fence posts, and harsh angles of staircases. It’s telling that even the soundproofed rooms have see-through doors with which to keep tabs on their occupants. Alfredson alums Hoyte Van Hoytema and Dino Jonsäter replicate the clinical approach to the cinematography and editing as they applied to Right One, while the production and costume design evoke the era flawlessly, and the sound design nicely captures clandestine rooftop meetings (held just out of earshot) when not melding the flapping of pigeon wings with the clickety-clack of a teletype machine coding its latest transmission. Alberto Iglesias’ low, jazzy score rounds out the technical end of things rather nicely, appropriate to a mood both morally and visually murky.

Of course, it would all be for naught if the ensemble didn’t bring it all home. Each man lends a critical hint of either vulnerability, volatility, or both to their cryptic roles, with Cumberbatch standing out as the most apparently conflicted of the tweed-cloaked lot. (When Smiley sends Peter on a mission to spy on his own, it’s a fairly taut exercise in avoiding the rather commonplace traps of protocol.) Hurt comes off as stubborn enough to have earned his seat at the head of the table, Jones is perfectly troll-like in his efforts to claim the throne for himself, and Hinds is similarly blustery when he needs to be. Dencik’s sycophancy is never overplayed -- the same goes for Firth’s sympathy -- while Strong and Hardy respectively represent soldiers strong and weak in their emotional dealings.

Looming above them all is Oldman, never more taciturn or calculating. Smiley hardly raises his voice or bats an eye in the face of unveiled betrayals, a ghost among spooks whose house is now an empty home. Mrs. Smiley barely makes an appearance, but certainly makes an impression, and in what amounts to Oldman’s big speech, he recalls the occasion on which he said too much and tipped the balance of trust too far. This spy game has possibly cost him his marriage, but that won’t stop him from rooting out the deeply platonic and discreetly romantic relationships that lurk, sometimes harmlessly, beneath his career surroundings. It’s a wonderfully subdued performance.

The treachery, once ultimately revealed, boils down to the camaraderie and compromise inherent to Cold War-era collaboration, a quality evenly shared between the suspects. In a field defined by subterfuge, disillusionment comes part and parcel with deceit. Whenever the narrative jumps back to a company Christmas party -- where everyone knows the Russian national anthem well enough to sing along -- the sinister gives way to something more bittersweet, as we witness a generation both united and undone by its shared mistrust in some unseen foe.

At another point in time, the camera passes a dismantled dragon-shaped playground slide on the street, an indication of fragmented innocence and a reminder that Smiley and Alfredson alike are deliberately taking apart a beast, piece by piece. The end result is enthralling, if not in the conventional sense of the slam-bang spy thriller. Take a deep breath. Take a closer look.